It is known that in lighting ignition circuits for igniting a gas discharge lamp, such as an automotive high intensity discharge (HID) headlamp, the ignition voltage is traditionally obtained by resistance-capacitance (R-C) networks, or other voltage-conditioning networks at the ballast side of the lighting ignition circuit. An ignition pulse can be generated across the lamp when the primary winding of a high voltage (HV) ignition transformer receives a voltage from the R-C network or the voltage-conditioning network.
One common disadvantage of such ignition circuits is that, unless a relatively high turn-ratio HV ignition transformer is utilized, the voltage from the R-C network or the voltage-conditioning network (applied at the primary side of the HV transformer) is not sufficiently high to develop the required break down voltage across a spark gap in series with the primary side of the HV transformer. As a consequence of using a transformer with a high turn-ratio, the electromagnetic coupling effected between the primary and secondary windings of the HV transformer is somewhat lossy. Moreover, having to use a high turn-ratio HV transformer increases the costs of assembly and/or manufacturing of the HV transformer, and also leads to increases in the size and weight of the transformer. Thus, it is desirable to provide a lighting ignition circuit that in a cost-effective manner addresses the foregoing issues.